The invention relates to a digital protection system for an electricity network for causing circuit breakers to open in the event of faults being sensed by current and/or voltage sensors on lines of the network connected to the circuit breakers, the system including a data transmission link with a remote appliance.
Such a protection system is used more particularly in high voltage electricity substations. It generally comprises a processor which receives the current values and/or voltage values as measured by the sensors mounted on the monitored lines of the network, which compares these measured current and/or voltage values with corresponding reference values, and which causes one or more circuit breakers to be opened when the measured current and/or voltage values exceed the corresponding reference values, so as to break the faulty line(s) of the electricity network.
Until now, in order to input reference values into the protection system, a portable computer has been used which is connected to the protection system by means of a data transmission link of the wire type. The portable computer makes it possible not only to input these reference values easily by means of its keyboard, but it also gives the operator a greater variety of options in modifying them and in displaying them on the screen. Nevertheless, because the portable computer is connected to the protection system by means of a wire type data transmission link, it can be subjected to disturbances and misfunctions due to the severe electromagnetic environment that exists inside an electricity substation around the protection system. In addition, a portable computer is a relatively fragile appliance that is bulky and ill-suited to the conditions of use in a high voltage electricity substation.
The object of the invention is to remedy those drawbacks.
To this end, the invention provides a digital protection system for an electricity network for causing circuit breakers to open in the event of faults being sensed by current and/or voltage sensors on lines of the network connected to the circuit breakers, the system including a data transmission link with a remote appliance, wherein said transmission link is an infrared link and said data transmission uses the wireless application protocol WAP.
In a particular embodiment of the protection system of the invention, the remote appliance is a mobile telephone, and in particular a so-called xe2x80x9csecond generationxe2x80x9d mobile telephone fitted with an infrared communications port which can be configured to communicate via said port using the wireless application protocol WAP. This type of telephone is already available on the market and has a screen of reasonable dimensions together with keys and software for browsing the Internet. It will thus be understood that a protection system containing a program for inputting, modifying, and displaying values and that is compatible with Internet browser software can be parameterized very easily and at low cost by means of a mobile telephone that is small in size and low in cost. Furthermore, the radio data transmission link makes it possible to obtain very safe metallic isolation between the protection system and the mobile telephone.